Tricyclic 1h-imidazole-5-carboxylic acid derivatives and use thereof as herbicides

ABSTRACT

Novel herbicidal tricyclic 1H-imidazole-5-carboxylic acid derivatives, compositions containing these compounds as active ingredients, and a method for controlling weeds, preferably selectively in crops of useful plants.

BACKGROUND OF THE INVENTION

A number of 1H-imidazole-5-carboxylic acid derivatives are known fromU.S. Pat. No. 3,485,917 as antifungal agents. Further, some of thesecompounds are described as active agents in a method for inhibiting budgrowth in U.S. Pat. No. 3,873,297.

DESCRIPTION OF THE INVENTION

The present invention is concerned with herbicidally active tricyclic1H-imidazole-5-carboxylic acid derivatives having the formula ##STR1## astereochemically isomeric form thereof, or a salt thereof, wherein

R¹ is hydrogen or mercapto,

R² is hydrogen, C₁ -C₇ alkyl, C₃ -C₇ alkenyl, C₃ -C₇ alkynyl, C₃ -C₇cycloalkyl, C₁ -C₇ alkyloxy-C₁ -C₇ alkyl or arylC₁ -C₅ alkyl;

X is a radical of formula ##STR2## wherein Y is O, S(O)_(m), NR⁹ or CH₂;

wherein m is zero, one or two;

R⁹ is hydrogen, C₁ -C₅ alkyl, C₁ -C₅ alkanoyl or 4-methylphenylsulfonyl;

n is 1, 2 or 3;

A is a C₁ -C₅ alkanediyl or a C₅ -C₇ cycloalkanediyl radical;

R³, R⁴, R⁵ and R⁶ are each independently hydrogen, C₁ -C₅ alkyl, mono-and di(aryl)C₁ -C₅ alkyl, C₁ -C₅ alkyloxy, halo, C₃ -C₇ alkenyl, C₁ -C₅alkyl substituted with one to three halo atoms, C₁ -C₅ alkyloxysubstituted with one to three halo atoms, or aryl;

whereby the radicals R³, R⁴ and the bivalent radical A as defined abovemay be substituted on any carbon atom making up the Y-containing part ofthe tricyclic ring system, including any of the CH₂ moieties of the--(CH₂)_(n) -- and Y fragments; provided that the bivalent radical A isnot connected to the same carbon atom thus forming a spirocyclic ringsystem;

R⁷ and R⁸ are each independently hydrogen, C₁ -C₅ alkyl, C₁ -C₅alkyloxy, halo, C₁ -C₅ alkyl substituted with one to three halo atoms,C₁ -C₅ alkyloxy substituted with one to three halo atoms, cyano, nitro,amino, mono- and di-C₁ -C₅ alkylamino or C₁ -C₆ alkylcarbonylamino; and

aryl is phenyl optionally substituted with one to three substituentseach independently selected from C₁ -C₅ alkyl, C₁ -C₅ alkyloxy and halo.

Surprisingly, the compounds of formula (I) show strong herbicidalproperties and are therefore useful to control weeds. These propertiesgain importance by the fact that some crops of useful plants are notdamaged, or are only slightly harmed when treated with compounds offormula (I) at high dosages. Consequently, the compounds of formula (I)are valuable selective herbicides in crops of useful plants, such assugar-beet, rape, soybeans, cotton, sunflower, cereals, especiallywheat, barley, rye and oats, rice, both upland rice and paddy rice, andmaize. Especially in rice crops a broad range of application rates canbe employed, preferably if the rice crops are transplanted rice crops,and if the compounds of formula (I) are applied after transplantation.In maize crops selective herbicidal action is observed both atpreemergence and at postemergence treatment.

The active ingredients (a.i.) of formula (I) are usually applied atapplication rates of 0.01 to 5.0 kg of active ingredient per hectare inorder to achieve satisfying results. Sometimes, depending on theenvironmental conditions, the application rates may exceed the abovedesignated limitations. However, the preferred application rates arebetween 0.05 kg and 1.0 kg a.i. per hectare.

As used in the foregoing definitions C₁ -C₅ alkyl denotes straight orbranch chained saturated hydrocarbon radicals having from 1 to 5 carbonatoms, e.g. methyl, ethyl, propyl, 1-methylethyl, the four butylisomers, the pentyl isomers; C₁ -C₇ alkyl includes C₁ -C₅ alkyl radicalsand the higher homologs thereof having 6 to 7 carbon atoms; halo isfluoro, chloro, bromo or iodo, with fluoro and chloro being preferred;C₃ -C₇ alkenyl defines straight and branch chained hydrocarbon radicalscontaining one double bond and having from 3 to 7 carbon atoms such as,for example, 2-propenyl, 3-butenyl, 2-butenyl, 2-pentenyl, 3-pentenyl,2-methyl-2-propenyl, or 3-methyl-2-butenyl, with 2-propenyl and2-methyl-2-propenyl being preferred; C₃ -C₇ alkynyl defines straight andbranch chained hydrocarbon radicals containing one triple bond andhaving from 3 to 7 carbon atoms such as, for example, 2-propynyl,2-butynyl, 3 -butynyl, 2-pentynyl, 3-pentynyl or 4-pentynyl, with2-propynyl being preferred; and when said C₃ -C₇ alkenyl or C₃ -C₇alkynyl are substituted on a heteroatom, then the carbon atom of said C₃-C₇ alkenyl or C₃ -C₇ alkynyl connected to said heteroatom, issaturated; C₃ -C₇ cycloalkyl defines cyclopropyl, cyclobutyl,cyclopentyl, cyclohexyl and cycloheptyl, with cyclopentyl and cyclohexylbeing preferred; and C₁ -C₅ alkanoyl denotes formyl, acetyl, propionyl,butyryl, 2-methylpropionyl, 4-methylbutyryl, 3-methylbutyryl or2,2-dimethylpropionyl.

As typical examples of mono- and di-(aryl)C₁ -C₅ alkyl there may bementioned phenylmethyl, phenylethyl, 4-chlorophenylmethyl,4-chlorophenylethyl, 4-methoxyphenylmethyl, 3-methoxyphenylmethyl ordiphenylmethyl with phenylmethyl being preferred.

As typical examples of halo substituted C₁ -C₅ alkyl and halosubstituted C₁ -C₅ alkyloxy there may be mentioned fluoromethyl,trifluoromethyl, difluoromethyl, chloromethyl, difluoromethoxy and thelike.

C₁ -C₅ alkanediyl denotes saturated bivalent straight or branch chainedhydrocarbon radicals having from 1 to 5 carbon atoms, e.g., methylene,1,2-ethanediyl, 1,3-propanediyl, 1,4-butanediyl and 1,5-pentanediyl.

C₅ -C₇ cycloalkanediyl is generic to, for example, 1,2-cyclopentanediyl,1,3-cyclopentanediyl, 1,2-cyclohexanediyl, 1,4-cyclohexanediyl and1,2-cycloheptanediyl.

C₁ -C₅ alkanoyl defines formyl, acetyl, propionyl, butyryl, isobutyryl,valeryl, isovaleryl or pivaloyl.

The polycyclic system of formula X attached to the imidazole ringencompasses the following basic structures, which may be unsubstitutedor substituted with the substituents R³, R⁴, R⁵, R⁶, R⁷ and R⁸ asdefined hereinabove: ##STR3##

The compounds of formula (I) contain at least one asymmetrical carbonatom, namely the carbon atom of the group X bearing the imidazolemoiety, and therefore may exist under different stereochemicallyisomeric forms. Unless otherwise mentioned or indicated, the chemicaldesignation of compounds denotes the mixtures of all stereochemicallyisomeric forms. These mixtures contain all diastereomeres andenantiomeres of the basic molecular structure and are intended to beembraced within the scope of the invention.

The absolute configuration of each chiral center may be indicated by thestereochemical descriptors R and S, this R and S notation correspondingto the rules described in Pure Appl. Chem. 1976, 45, 11-30. The relativeconfiguration of the asymmetric centres in the compounds of formula (I)is denoted by cis and trans and where appropriate by the terms α and β,these stereochemical descriptors being used according to the rulesdescribed in Chemical Abstracts 1977 Index Guide, Appendix IV, § 203. Insome compounds the stereochemical configuration is not experimentallydetermined. In those cases it is conventionally agreed to designate thestereochemically isomeric form which is first isolated as "A" and thesecond as "B", without further reference to the actual stereochemicalconfiguration.

Pure stereochemically isomeric forms of the compounds of formula (I) maybe obtained by the application of art-known separation methods such asselective crystallization and chromatographic techniques, e.g., countercurrent distribution, column chromatography, high performance liquidchromatography and the like. Preferably, if a specific stereochemicalform is desired, said compound will be synthesized by stereoselectivemethods of preparation. These methods will advantageously employenantiomerically pure starting materials.

The invention also comprises the salts which the compounds of formula(I) are able to form with organic or inorganic bases such as amines,alkali metal bases and earth alkaline metal bases, or quaternaryammonium bases, or with organic or inorganic acids, such as mineralacids, sulfonic acids, carboxylic acids or phosphorus containing acids.

Examples of salt-forming mineral acids are hydrofluoric acid,hydrochloric acid, hydrobromic acid, hydroiodic acid, sulfuric acid,nitric acid, chloric acid, perchloric acid or phosphoric acid. Preferredsalt-forming sulfonic acids are 4-methylbenzenesulfonic acid,benzenesulfonic acid, methanesulfonic acid or trifluoromethanesulfonicacid. Preferred salt-forming carboxylic acids are acetic acid,trifluoroacetic acid, benzoic acid, chloroacetic acid, phthalic acid,maleic acid, malonic acid and citric acid. Phosphorus containing acidsare the various phosphonous acids, phosphonic acids and phosphinicacids.

Preferred salt-forming alkali metal hydroxides and earth alkaline metalhydroxides are the hydroxides of lithium, sodium, potassium, magnesiumor calcium, most preferably those of sodium or potassium. Examples ofsuitable salt-forming amines are primary, secondary and tertiaryaliphatic and aromatic amines such as methanamine, ethanamine,1-propanamine, 2-propanamine, the four butanamine isomers,N-methylmethanamine, N-ethylethanamine,2-[(2-hydroxyethyl)amino]ethanol, N-propyl-1-propanamine,N-(1-methylethyl)-2-propanamine, N-butyl-1-butanamine, pyrrolidine,piperidine, morpholine, N,N-dimethylmethanamine, N,N-diethylethanamine,N,N-dipropyl-1-propanamine, quinuclidine, pyridine, quinoline andisoquinoline. Preferred amines are ethanamine, 1-propanamine,N-ethylethanamine or N,N-diethylethanamine, with 2-propanamine,2-[(2-hydroxyethyl)amino]ethanol and 1,4-diazabicyclo[2.2.2]octane beingmost preferred. Examples of quaternary ammonium salts generally containcations arising from ammonium hydroxides or ammonium halide salts, e.g.the tetramethylammonium, the trimethylphenylmethylammonium cation, thetriethylphenylmethylammonium, and also the ammonium cation.

Preferred compounds within the present invention are those compounds offormula (I) wherein R² is hydrogen or C₁ -C₇ alkyl; Y is O, S or CH₂ ; Ais a C₁ -C₅ alkanediyl group being substituted with R⁵ and R⁶ ; and R⁷and R⁸ are each independently hydrogen, halo, C₁ -C₅ alkyl, C₁ -C₅alkyloxy, cyano or C₁ -C₆ alkylcarbonylamino. Particularly preferredcompounds are those preferred compounds wherein Y is O or CH₂ ; A isC₃₋₅ alkanediyl; R³, R⁴, R⁵ and R⁶ are each independently hydrogen orC₁₋₅ alkyl. More particularly preferred compounds are those particularlypreferred compounds wherein R² is hydrogen, methyl or ethyl; n is 1 or2; A is a C₃ -C₄ alkanediyl group; R³, R⁴, R⁵ and R⁶ are eachindependently hydrogen or methyl; and R⁷ and R⁸ are each independentlyhydrogen, methyl, methoxy or halo. The most preferred compounds withinthe scope of the present invention are selected from methyl1-(1,2,3,4,4a,9a-hexahydro-9H-fluoren-9-yl)-1H-imidazole-5-carboxylateand methyl1-(5,6,7,8-tetrahydro-5,8-methano-9H-benzocyclohept-9-yl)-1H-imidazole-5-carboxylate,the salts or stereochemically isomeric forms thereof.

The preparation of the compounds of formula (I) is generally carried outby the following methods.

The compounds of formula (I) can be obtained by condensing a compound offormula ##STR4## wherein R² and X are as defined hereinabove, with a C₁-C₄ alkyl ester of formic acid in the presence of suitable base such as,for example, an alkali metal alkoxide or hydride, e.g. sodium methoxide,potassium ethoxide, sodium hydride, lithium hydride, and the like, in areaction-inert solvent; and treating the resulting intermediate offormula ##STR5## wherein R² and X are as defined hereinabove and M is analkali metal atom,

(a) with an alkali metal isothiocyanate in the presence of an acid, thusobtaining a 2-mercaptoimidazole of formula ##STR6## wherein R² and X areas defined hereinabove, which optionally is converted into a compound ofthe formula ##STR7## by reacting the starting compound with nitric acidoptionally in the presence of an alkali metal nitrite, e.g. sodiumnitrite; or with Raney-nickel in the presence of a lower aliphaticalcohol, preferably ethanol, at a temperature between 40° C. and 80° C.;or also by treating the starting compounds (I-a) with an aqueoushydrogen peroxide solution preferably in the presence of a carboxylicacid, e.g. acetic acid; or (b) with a carboxylic acid amide of 1 to 3carbon atoms, preferably formamide, in the presence of an acid at atemperature between 50° C. and 250° C., preferably between 120° C. and170° C.; or (c) with an excess of ammonium carbonate or hydrogencarbonate in a suitable solvent, which may be a reaction-inert solventor an acid, at a temperature between 20° C. and 200° C., preferablybetween 25° C. and the reflux temperature of the reaction mixture.

In the afore-mentioned processes reaction-inert solvents are, forexample, aromatic hydrocarbons such as benzene, methylbenzene ordimethylbenzene; ethers such as, for example, 1,1'-oxybisethane,tetrahydrofuran or dioxane; or other aprotic organic solvents. For thecyclization-reaction of the imidazole ring structure, strong mineralacids such as hydrohalic acids, e.g. hydrochloric acid, are mostconveniently employed. In the ring-forming variant (c) also other acids,e.g. acetic acid, can be used. In this reaction an excess of acid of 5to 50, preferably of 15 to 40 times the required molar amount is mostpreferably used. The excess of ammonium salt in this process is 2 to 50,preferably 10 to 30 times the required molar amount.

The compounds of formula (I-b) can also be prepared by the deaminationreaction of a 4-amino-1H-imidazole derivative of formula (IV), whereinR² and X are as defined under formula (I). Said deamination reactioninvolves a diazotation and a reductive dediazotation step which may beconducted sequentially, i.e. with isolation of the intermediatediazonium salt (IV-a) or in a one-pot fashion wherein said diazoniumsalt is reduced in situ. ##STR8## Treatment of the 4-amino-1H-imidazolederivative of formula (IV) in aqueous medium with an alkali metalnitrite, e.g. sodium or potassium nitrite, in the presence of an acidsuch as hydrochloric acid, sulfuric acid or nitric acid, or withnitronium tetrafluoroborate (NO⁺ BF₄ ⁻) yields the diazonium salt(IV-a). In the latter, R² and X are as defined under formula (I) and A⁻represents an anion corresponding to the conjugated base of the acidemployed in the diazotation reaction or the tetrafluoroborate anion. Theintermediate diazonium salts (IV-a) are reduced to the compounds offormula (I-b) by treatment with an appropriate reductant such ashypophosphoric acid at an elevated temperature, preferably at theboiling temperature of the reaction mixture.

Alternatively, treatment of the 4-amino-1H-imidazole derivatives offormula (IV) with a C₁₋₅ alkyl nitrite such as, 1,1-dimethylethylnitrite or 1,2-dimethylpropyl nitrite in suitable aprotic solvent suchas tetrahydrofuran, 1,4-dioxane, trichloromethane orN,N-dimethylformamide yields a compound of formula (I-b) directly. Thelatter deamination reaction may conveniently be conducted at an elevatedtemperature, generally at the boiling point of the reaction mixture.

The compounds of formula (I) can also be converted into each otherfollowing art-known functional group transformation reactions.

The substituent R² on the carboxylic acid group may be transformed toother substituents encompassed by the definition of R² by suitablereactions known in the art for the modification of carboxylic acidfunctions, e.g. by hydrolysis and esterification and/ortransesterification.

Y being --S-- may be converted to the corresponding sulfoxide or sulfoneby an approprioate oxidation procedure, e.g. by treatment with aperoxide or a periodate.

Some of the starting materials for the preparation of the compounds offormula (I) are known, while others are new and can be obtained by knownsynthesis procedures.

For example, the compounds of formula (II) can be obtained byN-formylating a glycine ester of formula

    X--NH--CH.sub.2 --COOR.sup.2                               (V)

wherein R² and X are as defined hereinabove, with formic acid in thepresence of acetic anhydride. In turn, the compounds of formula (V) canbe prepared by N-alkylation an amine of formula

    X--NH.sub.2                                                (VI)

wherein X is as defined under formula (I), with an α-haloacetic acidester, e.g. α-bromoacetic ester, of formula

    Br--CH.sub.2 --COOR.sup.2                                  (VII)

wherein R² is as defined under formula (I). The reaction of (VI) with(VII) is conveniently conducted in a reaction-inert solvent, e.g.tetrahydrofuran, 1,1'-oxybisethane, N,N-dimethylformamide ordichloromethane, in the presence of a base such as an alkali metalcarbonate, e.g. sodium carbonate.

The 4-amino-1H-imidazole derivatives of formula (IV) can be obtained bycyclizing an intermediate of formula ##STR9## wherein X and R² are asdefined hereinabove under catalysis of a base at elevated temperature ina suitable solvent, e.g. an alcohol. A preferred mode of carrying outsaid cyclization may comprise the reaction of the starting compound(VIII) in an alcohol, preferably that alcohol of which the ester groupCOOR² is derived, in the presence of a catalytic amount of alkoxideobtained by dissolving an alkali metal in said alcohol, at the boilingpoint of the reaction mixture. Or, alternatively, by reacting (VIII)with an alkali metal alkoxide wherein the alkoxide preferably is OR² ina polar solvent such as N,N-dimethylformamide or dimethyl sulfoxide.Generally, the reaction temperatures are in the range of +60° C. to+140° C.

The intermediates of formula (VIII) in turn can be prepared byalkylating an amidine of formula

    NC--N═CH--NH--X                                        (IX)

wherein X is as defined under formula (I) with an α-haloacetic acidester of formula (VII), in the presence of an appropriate base, such as,for example an alkali metal hydroxide, an alkali or earth alkaline metalcarbonate or hydrogen carbonate, an earth alkaline oxide, an alkalimetal alkoxide or a trialkylamine, e.g. sodium hydroxide, potassiumhydroxide, sodium carbonate, potassium hydrogen carbonate, magnesiumoxide, calcium oxide, sodium methoxide, sodium ethoxide, potassiumethoxide, potassium isopropoxide, pyridine, N,N-diethylethanamine andthe like. In some instances, the addition of a crown-ether may berecommendable. The reaction may conveniently be conducted attemperatures between +10° C. and the boiling point of the reactionmixture, either without a solvent or in a solvent such asN,N-dimethylformamide, N,N-dimethylacetamide or dimethyl sulfoxide.

The compounds of formula (IX) can be prepared by reacting an amine offormula (VI) with a C₁₋₅ alkyl-N-cyanomethanimidate of formula

    C.sub.1-5 alkyl--O--CH═N--CN                           (X)

in an appropriate reaction-inert solvent such as trichloromethane,tetrahydrofuran, 1,4-dioxane, acetonitrile, N,N-dimethylformamide orN,N-dimethylacetamide. The said reaction can conveniently be carried outat temperatures between room temperature and the boiling point of thereaction mixture, in particular between +20° C. and +80° C. Removal ofthe C₁₋₅ alkanol which is liberated during the course of the reactionand of the solvent by destillation under reduced pressure yields theN-cyanoamidine of formula (IX) which in general need not be purifiedbefore further convertion.

The 4-amino-1H-imidazole derivatives of formula (IV) can alternativelybe obtained from the amines of formula (VI), by a combined N-alkylatingand cyclization reaction in a one-pot procedure. The latter procedure isconducted in the same solvents and bases as mentioned hereinabove forthe two step synthesis.

The amines of formula (VI) can be obtained by the reduction of an oximeof formula ##STR10## wherein R³, R⁴, R⁵, R⁶, R⁷, R⁸, Y, A and n are asdefined hereinabove. Said reduction is conveniently conducted withhydrogen in the presence of a noble metal catalyst or with a hydridereagent, e.g. lithium tetrahydroaluminate or diborane in a suitablereaction-inert solvent such as an ether, e.g. tetrahydrofuran,1,1'-oxybisethane and the like. The oxime of formula (XI) may also bereduced electrochemically.

Said hydroxylamine (XI) in turn, is prepared from the correspondingketone of formula ##STR11## wherein R³, R⁴, R⁵, R⁶, R⁷, R⁸, Y,A and nare as defined hereinabove, by reacting said ketone of formula (XII)with hydroxylamine.

The intermediates of formula (V) can also be prepared by the reductiveN-alkylation of a ketone of formula (XII) with a glycine ester (XIII)wherein R² is as defined under formula (I). ##STR12## Said reductiveN-alkylation reaction may conveniently be carried out by hydrogenating astirred and, if desired, heated mixture of the reactants in a suitablereaction-inert organic solvent according to art-known catalytichydrogenating procedures. Suitable solvents are, for example, alkanols,e.g. methanol, ethanol; ethers, such as tetrahydrofuran. The term"art-known catalytic hydrogenating procedures" means that the reactionis carried out under hydrogen atmosphere and in the presence of acatalyst such as, palladium-on-charcoal, platinum-on-charcoal and thelike. In order to prevent the undesired further hydrogenation of certainfunctional groups in the reactants and the reaction products it may beadvantageous to add an appropriate catalyst-poison to the reactionmixture, e.g. thiophene.

Alternatively, said reductive N-alkylation reactions may be conducted bytreating a stirred and, if desired, heated mixture of the reactants withsodium cyanoborohydride, sodium borohydride, formic acid or a saltthereof, e.g. ammonium formiate.

Typical preparation methods of the ketones of formula (XI) are describedin e.g. J. Org. Chem. 1967, 32, 3358, J. Org. Chem. 1970, 35, 1183, J.Org. Chem. 1978, 43, 849, J. Org. Chem. 1985, 50, 5132, J. Am. Chem.Soc. 1960, 82, 1457-1462, J. Am. Chem. Soc. 1948, 70, 974, J. Am. Chem.Soc. 1973, 95, 5659.

The compounds of formula (I) are stable compounds and no precautionarymeasures are required for handling them.

When used at the indicated rates of application, the compounds offormula (I) have good selective herbicidal properties which make themmost suitable for use in crops of useful plants, in particular in sugarbeet, soybeans, cereals and preferably in maize and rice. In some casesdamage is also caused to weeds which up to now have only been controlledwith total herbicides.

At higher rates of application, all tested plants are so severelydamaged in their development that they die.

The invention also relates to herbicidal compositions containing one ormore inert carriers and, if desired, other adjuvants and as an activeingredient a herbicidally effective amount of a compound of formula (I)as defined hereinabove. Further the invention relates to a method ofcontrolling weeds, said method comprising the application to said weedsor to the locus thereof of a herbicidally effective amount of a compoundof formula (I), a stereoisomeric form thereof or a salt.

In the method for controlling weeds according to the invention thecompounds of formula (I) are used in unmodified form or, preferably,together with the adjuvants conventionally employed in the art offormulation. They are therefore formulated following art-knownprocedures to emulsifiable concentrates, directly sprayable or dilutablesolutions, dilute emulsions, wettable powders, soluble powders, dusts,granulates, and also encapsulations in e.g. polymer substances. As withthe nature of the compositions, the methods of application, such asspraying, atomising, dusting, scattering or pouring, are chosen inaccordance with the intended objectives and the prevailingcircumstances.

The formulations, i.e. the compositions, preparations or mixturescontaining the compound (active ingredient) of formula (I) and, whereappropriate, a solid or liquid adjuvant, are prepared by known means,e.g. by homogeneously mixing and/or grinding the active ingredients withextenders, e.g. solvents, solid carriers and, where appropriate,surface-active compounds (surfactants).

Suitable solvents are aromatic hydrocarbons, preferably the fractionscontaining 8 to 12 carbon atoms, e.g. dimethylbenzene mixtures orsubstituted naphthalenes, phthalates such as dibutyl phthalate ordioctyl phthalate, aliphatic or alicyclic hydrocarbons such ascyclohexane or paraffins, alcohols and glycols and their ethers andesters, such as ethanol, ethylene glycol, ethylene glycol monomethyl ormonoethyl ether, ketones such as cyclohexanone, strongly polar solventssuch as N-methyl-2-pyrrolidone, dimethylsulfoxide or dimethylformamide,as well as vegetable oils or epoxidised vegetable oils such asepoxidised coconut oil or soybean oil; or water.

The solid carriers used e.g. for dusts and dispersible powders arenormally natural mineral fillers such as calcite, talcum, kaolin,montmorillonite or attapulgite. In order to improve the physicalproperties it is also possible to add highly dispersed silicic acid orhighly dispersed absorbent polymers. Suitable granulated absorbentcarriers are of the porous type, for example pumice, broken brick,sepiolite or bentonit; and suitable nonsorbent carriers are materialssuch as calcite or snd. In addition, a great number of pregranulatedmaterials of inorganic or organic nature can be used, e.g. especiallydolomite or pulverised plant residues.

Depending on the nature of the compound of formula (I) to be formulated,suitable surface-active compounds are non-ionic, cationic and/or anionicsurfactants having good emulsifying, dispersing and wetting properties.The term "surfactants" will also be understood as comprising mixtures ofsurfactants.

Suitable anionic surfactants can be both water-soluble soaps andwater-soluble synthetic surface-active compounds.

Suitable soaps are the alkali metal salts, earth alkaline metal salts orunsubstituted or substituted ammonia salts of higher fatty acids (C₁₀-C₂₂), e.g. the sodium or potassium salts of oleic or stearic acid, orof natural fatty acid mixtures which can be obtained e.g. from coconutoil or tallow oil. In addition, there may also be mentioned fatty acidmethyltaurin salts.

More frequently, however, synthetic surfactants are used, especiallyfatty sulfonates, fatty sulfates, sulfonated benzimidazole derivativesor alkylarylsulfonates.

The fatty sulfonates or sulfates usually occur as alkali metal salts,earth alkaline metal salts or unsubstituted or substituted ammoniumsalts and contain an alkyl radical consisting of 8 to 22 carbon atoms,said alkyl also comprising radicals derived from acyl groups of fattyacids, e.g. the sodium or calcium salt of lignosulfonic acid, ofdodecylsulfate or of a mixture of fatty alcohol sulfates obtained fromnatural fatty acids. These compounds also comprise the salts of sulfuricacid esters and sulfonic acids of fatty alcohol/ethylene oxide adducts.The sulfonated benzimidazole derivatives preferably contain 2 sulfonicacid groups and one fatty acid radical containing 8 to 22 carbon atoms.Examples of alkylarylsulfonates are the sodium, calcium ortriethanolamine salts of dodecylbenzene sulfonic acid,dibutylnaphthalenesulfonic acid, or of a naphthalenesulfonicacid/formaldehyde condensation product. Also suitable are correspondingphosphates, e.g. salts of the phosphoric acid ester of an adduct ofp-nonylphenol with 4 to 14 moles of ethylene oxide, or phospholipids.

Non-ionic surfactants are preferably polyglycol ether derivatives ofaliphatic or cycloaliphatic alcohols, or saturated or unsaturated fattyacids and alkylphenols, said derivatives containing 3 to 10 glycol ethergroups and 8 to 20 carbon atoms in the (alifatic) hydrocarbon moiety and6 to 18 carbon atoms in the alkyl moiety of the alkylphenols.

Further suitable non-ionic surfactants are the water-soluble adducts ofpolyethylene oxide with polypropylene glycol,ethylenediaminopolypropylene glycol containing 1 to 10 carbon atoms inthe alkyl chain, which adducts contain 20 to 250 ethyl glycol ethergroups and 10 to 100 propylene glycol ether groups. These compoundsusually contain 1 to 5 ethylene glycol units per propylene glycol unit.

Representative examples of non-ionic surfactants arenonylphenolpolyethoxyethanols, castor oil polyglycol ethers,polypropylene/polyethylene oxide adducts,tributylphenoxypolyethoxyethanol, polyethylene glycol andoctylphenoxypolyethoxyethanol.

Fatty acid esters of polyethylene sorbitan, such as polyoxyethylenesorbitan trioleate, are also suitable non-ionic surfactants.

Cationic surfactants are preferably quaternary ammonium salts whichcontain, as N-substituent, at least one C₈ -C₂₂ alkyl radical and, asfurther substituents, unsubstituted or halogenated lower alkyl, benzylor hydroxy-lower alkyl radicals. The salts are preferably in the form ofhalides, methylsulfates or ethylsulfates, e.g. stearyltrimethylammoniumchloride or benzyldi(2-chloroethyl)ethylammonium bromide.

The surfactants customarily employed in the art of formulation aredescribed e.g. in the following publications:

"McCutcheon's Detergents and Emulsifiers Annul", MC Publishing Corp.,Ridgewood, N.J., 1981; H. Stache, "Tensid-Taschenbuch", 2nd Edition, C.Hanser Verlag, Munich & Vienna, 1981, M. and J. Ash, "Encyclopedia ofSurfactants", Vol. I-III, Chemical Publishing Co., New York, 1980-81.

The herbicidal compositions which are preferably employed in the methodof the invention usually contain 0.1 to 95%, preferably 0.1 to 80%, of acompound of formula (I), 1 to 99.9%, of a solid or liquid adjuvant, and0 to 25%, preferably 0.1 to 25%, of a surfactant.

Preferred formulations are composed in particular of the followingconstituents (%=percentage by weight):

    ______________________________________                                        Emulsifiable concentrates                                                     active ingredient:                                                                           1 to 20%,  preferably 5 to 10%                                 surfactant:    5 to 30%,  preferably 10 to 20%                                liquid carrier:                                                                              50 to 94%, preferably 70 to 85%                                Dusts                                                                         active ingredient:                                                                           0.1 to 10%,                                                                              preferably 0.1 to 1%                                solid carrier: 99.9 to 90%,                                                                             preferably 99.9 to 99%                              Suspension concentrates                                                       active ingredient:                                                                           5 to 75%,  preferably 10 to 50%                                water:         94 to 25%, preferably 88 to 30%                                surfactant:    1 to 40%,  preferably 2 to 30%                                 Wettable powders                                                              active ingredient:                                                                           0.5 to 90%,                                                                              preferably 1 to 80%                                 surfactant:    0.5 to 20%,                                                                              preferably 1 to 15%                                 solid carrier: 5 to 95%,  preferably 15 to 90%                                Granulates                                                                    active ingredient:                                                                           0.5 to 30%,                                                                              preferably 3 to 15%                                 solid carrier: 99.5 to 70%,                                                                             preferably 97 to 85%                                ______________________________________                                    

The following examples are intended to illustrate and not to limit thescope of the present invention in all its aspects. Unless otherwisestated all parts therein are by weight.

EXPERIMENTAL PART

A. Preparation of Intermediates

EXAMPLE 1

(a) A mixture of 48 parts of 1,2,3,4,4a,9a-hexahydro-9H-fluoren-9-one,65 parts of methyl glycine hydrochloride, 65 parts of sodium acetate and560 parts of methanol was hydrogenated at normal pressure and at roomtemperature with 5 parts of palladium-on-charcoal catalyst 10%. Afterthe calculated amount of hydrogen was taken up, the catalyst wasfiltered off and the filtrate was evaporated. The residue was taken upin a mixture of water and trichloromethane. The whole was acidified witha hydrochloric acid solution. The separated aqueous layer was madealkaline and the product was extracted with trichloromethane. Thecombined organic layers were dried, filtered and evaporated, yielding16.6 parts (24.8%) of methylN-(1,2,3,4,4a,9a-hexahydro-9H-fluoren-9-yl)glycine as a residue (int.1).

(b) A mixture of 16.6 parts of methylN-(1,2,3,4,4a,9a-hexahydro-9H-fluoren-9-yl)glycine, 44 parts of formicacid and 11.9 parts of acetic acid anhydride was stirred overnight atroom temperature. The reaction mixture was poured into water and theproduct was extracted with trichloromethane. The extract was dried,filtered and evaporated, yielding 15.9 parts (86.4%) of methylN-formyl-N-(1,2,3,4,4a,9a-hexahydro-9H-fluoren-9-yl)glycine as a residue(int. 2).

EXAMPLE 2

A mixture of 23.4 parts of2,3,3a,8a-tetrahydrocyclopent[a]inden8(1H)-one, 31.4 parts of methylglycine hydrochloride, 1 part of a solution of thiophene in methanol 4%,400 parts of methanol and 13.3 parts of potassium acetate washydrogenated at normal pressure and at room temperature with 2.0 partsof palladium-on-charcoal catalyst 10%. After the calculated amount ofhydrogen was taken up, the catalyst was filtered off and the filtratewas evaporated. The residue was taken up in water and the product wasextracted with dichloromethane. The extract was washed with ahydrochloric acid solution and a sodium hydroxide solution, dried,filtered and evaporated, yielding 29.0 parts (86.9%) of methylN-(1,2,3,3a,8,8a-hexahydrocyclopent[a]inden-8-yl)-glycine as a residue(int. 3).

By the same method there were also prepared methylN-(1,1a,6,6a-tetrahydrocycloprop[a]inden-6-yl)glycine as a residue (int.4); and methylN-(5,6,7,8-tetrahydro-5,8-methano-9H-benzocyclohept-9-yl)glycine as aresidue (int. 5).

EXAMPLE 3

A mixture of 46.4 parts of2,3,4,4a,10,10a-hexahydro-9(1H)-phenanthrenone, 58 parts of methylglycine monohydrochloride, 2 parts of a solution of thiophene inmethanol 4%, 480 parts of methanol and 26.1 parts of potassium fluoridewas hydrogenated at normal pressure and at 50° C. with 3.0 parts ofpalladium-on-charcoal catalyst 10%. After the calculated amount ofhydrogen was taken up, the catalyst was filtered off and the filtratewas evaporated. The residue was taken up in water and 1,1'-oxybisethane.The whole was treated with a sodium hydroxide solution. The separatedorganic layer was dried, filtered and evaporated, yielding 59.5 parts(93.8%) of methyl N-(1,2,3,4a,9,10,10a-octahydro-9-phenanthrenyl)glycineas a residue (int. 6).

By the same method there was also prepared methyl[4aα,10β,10aα]-N-(1,2,3,4,4a,9a-hexahydro-9H-xanthen-9-yl)-glycine as aresidue (int. 7).

The glycine derivatives obtained in examples 2 and 3 subsequentlyN-formylated following the procedures described in example 1(b) andyielded respectively

methylN-formyl-N-(1,2,3,3a,8,8a-hexahydrocyclopent[a]inden-8-yl)-glycine as aresidue (int. 8);

methyl N-formyl-N-(1,1a,6,6a-tetrahydrocycloprop[a]inden-6-yl)glycine asa residue (int. 9);

methylN-formyl-N-(5,6,7,8-tetrahydro-5,8-methano-9H-benzocyclohept-9-yl)glycineas a residue (int. 10);

methylN-formyl-N-(1,2,3,4,4a,9,10,10a-octahydro-9-phenanthrenyl)-glycine as aresidue (int. 11) and

methyl(±[4aα,10β,10aα]-N-formyl-N-(1,2,3,4,4a,9a-hexahydro-9H-xanthen-9-yl)glycine(int. 12)

EXAMPLE 4

(a) 4.3 Parts of a syn-anti-mixture of9-oximino-1,2,3,4,4a,9,9a,10-octahydroanthracene were dissolved in 40 mlof tetrahydrofuran and 8.7 ml of methanolic hydrochloric acid. 1.3 Partsof a 10% palladium-on-carbon catalyst were added and the mixture washydrogenated with 896 ml gaseous hydrogen at 30°-35° C. and normalpressure within 30 minutes. The catalyst was filtered off, and thefiltrate concentrated. 4 Parts of9-amino-1,2,3,4,4a,9,9a,10-octahydroanthracene hydrochloride, mp.240°-245° C., were obtained. The hydrochloride was dissolved in water,and sodium hydroxide was added to adjust the pH-value to pH 8. Thealkaline solution was extracted with ether. The combined etheral phaseswere dried with Na₂ SO₄, filtered and concentrated. 2.8 Parts (70% oftheory) of 9-amino-1,2,3,4,4a,9,9a,10-octahydroanthracene (int. 13), mp.37°-39° C., were obtained. The amine-product consists of a mixture of atleast 3 stereochemical isomers.

(b) 20 Parts of 9-amino-1,2,3,4,4a,9,9a,10-octahydroanthracene weredissolved in 100 ml of ethanol. 9.8 Parts of ethyl N-cyano-formamidatewere added within 10 minutes and the mixture was heated to reflux. Thecooled solution was concentrated. 24.9 Parts (99% of theory) of crudeN-(1,2,3,4,4a,9,9a,10-octahydroanthracen-9-yl)-N'-cyano-formamidine(int. 14), mp. 145°-165° C. were obtained.

(c) 20.8 Parts ofN-(1,2,3,4,4a,9,9a,10-octahydroanthracen-9-yl)-N'-cyano-formamidine weredissolved in 140 ml of N,N-dimethylformamide together with 0.1 parts of18-crown-6. 28.4 Parts of potassium carbonate were added. The mixturewas heated to +80'C. and 13.8 Parts of α-bromo-methyl-acetate wereadded. After 15 hours at +80° C. to +100° C. the reactants were pouredon ice and the mixture was extracted with ether. The etheral extractswere dried with Na₂ SO₄, filtered and concentrated. 21 Parts of cruderesidue were chromatographed on a silica gel column and extracted withan ethyl acetate/hexane mixture (1:1). 11.6 Parts (43%) of methyl1-(1,2,3,4,4a,9,9a,10-octahydroanthracen-9-yl)-4-amino-1H-imidazole-5-carboxylate(int. 15), mp. 155°-159° C. were isolated.

B. Preparation of Final Compounds

EXAMPLE 5

(a) A mixture of 27.3 parts of methylN-formyl-N-(1,2,3,3a,8,8a-hexahydrocyclopent[a]inden-8-yl)glycine, 4.8parts of a sodium hydride dispersion 50%, 30 parts of methyl formate and225 parts of tetrahydrofuran was stirred overnight at room temperature.After the addition of 8 parts of methanol, the mixture was evaporated.The residue was taken up in water and 1,1'-oxybisethane. The separatedaqueous layer was acidified with concentrated hydrochloric acid and theproduct was extracted with dichloromethane. The extract was dried,filtered and evaporated. A mixture of the residue, 200 parts ofmethanol, 30 parts of concentrated hydrochloric acid, 19.5 parts ofpotassium thiocyanate and 250 parts of water was stirred onernight at60° C. After the addition of 450 parts of water, the product wasfiltered off and dried in vacuo at 60° C., yielding 15.1 parts (48.0%)of methyl(A)-1-(1,2,3,3a,8,8a-hexahydrocyclopent[a]inden-8-yl)-2-mercapto-1H-imidazole-5-carboxylate;mp. 154.2° C. (compound 4.1).

(b) A mixture of 14.1 parts of methyl(A)-1-(1,2,3,3a,8,8a-hexahydrocyclopent[a]inden-8-yl)-2-mercapto-1-H-imidazole-5-carboxylate,0.1 parts of sodium nitrite, 75 parts of concentrated nitric acid and150 parts of water was stirred for 1 hour at room temperature. After theaddition of crushed ice, the whole was treated with a sodium hydroxidesolution. The product was extracted with dichloromethane. The extractwas dried, filtered and evaporated. The residue was converted into thenitrate salt in a mixture of 1,1'-oxybisethane and 2-propanone. The saltwas filtered off and dried, yielding 11.1 parts (71.4%) of methyl(A)-1-(1,2,3,3a,8,8a-hexahydrocyclopent[a]inden-8-yl)-1H-imidazole-5-carboxylatemononitrate; mp. 148.1° C. (compound 4.2).

Following the same procedures there were also obtained:

methyl1-(1,2,3,4,4a,9a-hexahydro-9H-fluoren-9-yl)-1H-imidazole-5-carboxylatemononitrate; mp. 140.2° C. (compound 1.4);

methyl1-(1,1a,6,6a-tetrahydrocycloprop[a]inden-6-yl)-1H-imidazole-5-carboxylatemononitrate; mp. 169.0° C. (compound 4.9);

methyl1-(5,6,7,8-tetrahydro-5,8-methano-9H-benzocyclohept-9-yl)-1H-imidazole-5-carboxylatemonohydrochloride; mp. 153.6° C. (compound 5.2); and

methyl[4aα,10β,10aα]-1-(1,2,3,4,4a,9a-hexahydro-9H-xanthen-9yl)-1H-imidazole-5-carboxylatemononitrate, hemihydrate; mp. 184.6° C. (compound 2.20).

(c) A mixture of 8.8 parts of methyl(A)-1-(1,2,3,3a,8,8a-hexahydrocyclopent[a]inden-8-yl)-1H-imidazole-5-carboxylatemononitrate, 5 parts of a sodium hydroxide solution 50% and 250 parts ofwater was stirred for 2 hours at reflux temperature. The reactionmixture was acidifed with acetic acid. The precipitated product wasfiltered off and dried, yielding 5.45 parts (79.6%) of(A)-1-(1,2,3,3a,8,8a-hexahydrocyclopent[a]inden-8-yl)-1H-imidazole-5-carboxylicacid; mp. 216.6° C. (compound 4.3).

EXAMPLE 6

methyl2-mercapto-1-(1,2,3,4,4a,9,10,10a-octahydro-9-phenanthrenyl)-1H-imidazole-5-carboxylate(compound 3.1) was prepared following the reaction procedure describedin example 4(a).

A mixture of 19.0 parts of methyl2-mercapto-1-(1,2,3,4,4a,9,10,10a-octahydro-9-phenanthrenyl)-1H-imidazole-5-carboxylate,75 parts of nitric acid and 150 parts of water was stirred for 1 hour atroom temperature. The reaction mixture was diluted with crushed ice andtreated with a sodium hydroxide solution. The product was extracted with1,1'-oxybisethane. The extract was dried, filtered and evaporated. Theresidue was crystallized from acetonitrile. The product was filtered offand dried, yielding 1.9 parts (11.1%) of methyl1-(1,2,3,4,4a,9,10,10a-octahydro-9-phenanthrenyl)-1H-imidazole-5-carboxylate;mp. 139.9° C. (compound 3.2).

The latter compound and compound 5.2 were converted to their respectivecarboxylic acid following the saponification procedure described inexample 4(c), yielding

1-(1,2,3,4,4a,9,10,10a-octahydro-9-phenanthrenyl)-1H-imidazole-5-carboxylicacid (compound 3.3); and

1-(5,6,7,8-tetrahydro-5,8-methano-9H-benzocyclohept-9-yl)-1H-imidazole-5-carboxylicacid; mp. 230.0° C. (compound 5.3).

EXAMPLE 7

4.3 Parts of 1,1-dimethylethyl nitrite were dissolved in 40 mlN,N-dimethylformamide and heated to +60° C. A solution of 8 parts ofmethyl1-(1,2,3,4,4a,9,9a,10-octahydroanthracen-9-yl)-4-amino-1H-imidazole-5-carboxylatein 50 ml N,N-dimethylformamide was dropwise added at +60° C. After 1.5hour the solution was poured into water and extracted with ethylacetate. The organic phase was dried with Na₂ SO₄, filtered andconcentrated. The resulting 8.5 parts of crude material werechromatographed on a silica gel column with an ethyl acetate/hexanemixture (1:1). 2.9 Parts (38%) of methyl1-(1,2,3,4,4a,9,9a,10-octahydroanthracen-9-yl)-imidazole-5-carboxylate,mp. 151°-152° C. (compound 2.2), were obtained. According to ¹ H-NMR theproduct consists of an epimeric mixture of 2 isomers.

All other compounds listed in tables 1 to 6 can be obtained by analogousmethods of preparation.

    ______________________________________                                         ##STR13##                                                                    comp.                                  physical                               No.   R.sup.1                                                                              R.sup.2      R.sup.7                                                                              R.sup.8                                                                             data                                   ______________________________________                                        1.1   SH     CH.sub.3     H      H     solid residue                          1.2   H      CH.sub.3     H      H                                            1.3   H      H            H      H                                            1.4   H      CH.sub.3     H      H     .HNO.sub.3 /mp.                                                               140.2° C.                       1.5   H      CH.sub.3     H      H     cis                                    1.6   H      CH.sub.3     H      H     trans                                  1.7   SH     C.sub.2 H.sub.5                                                                            H      H                                            1.8   H      C.sub.2 H.sub.5                                                                            H      H                                            1.9   SH     i. C.sub.3 H.sub.7                                                                         H      H                                            1.10  H      i. C.sub.3 H.sub.7                                                                         H      H                                            1.11  SH     n. C.sub.3 H.sub.7                                                                         H      H                                            1.12  H      n. C.sub.3 H.sub.7                                                                         H      H                                            1.13  SH     n. C.sub.4 H.sub.9                                                                         H      H                                            1.14  H      n. C.sub.4 H.sub.9                                                                         H      H                                            1.15  SH     CH.sub.2 CHCH.sub.2                                                                        H      H                                            1.16  H      CH.sub.2 CHCH.sub.2                                                                        H      H                                            1.17  SH     CH.sub.2 CCH H      H                                            1.18  H      CH.sub.2 CCH H      H                                            1.19  SH     cyclohexyl   H      H                                            1.20  H      cyclohexyl   H      H                                            1.21  SH     CH.sub.2 OCH.sub.3                                                                         H      H                                            1.22  H      CH.sub.2 OCH.sub.3                                                                         H      H                                            1.23  SH     CH.sub.2 C.sub.6 H.sub.5                                                                   H      H                                            1.24  H      CH.sub.2 C.sub.6 H.sub.5                                                                   H      H                                            1.25  SH     CH.sub.3     6-F    H                                            1.26  H      CH.sub.3     6-F    H                                            1.27  H      H            6-F    H                                            1.28  SH     CH.sub.3     6-Cl   H                                            1.29  H      CH.sub.3     6-Cl   H                                            1.30  SH     CH.sub.3     6-Br   H                                            1.31  H      CH.sub.3     6-Br   H                                            1.32  SH     CH.sub.3     6-CH.sub.3 O                                                                         H                                            1.33  H      CH.sub.3     6-CH.sub.3 O                                                                         H                                            1.34  SH     CH.sub.3     6-CH.sub.3                                                                           H                                            1.35  H      CH.sub.3     6-CH.sub.3                                                                           H                                            1.36  SH     CH.sub.3     6-Cl   8-Cl                                         1.37  H      CH.sub.3     6-Cl   8-Cl                                         1.38  SH     CH.sub.3     6-CH.sub.3                                                                           8-CH.sub.3                                   1.39  H      CH.sub.3     6-CH.sub.3                                                                           8-CH.sub.3                                   ______________________________________                                    

    ______________________________________                                         ##STR14##                                                                    comp.                                                                         No.      R.sup.1 R.sup.2 R.sup.3                                                                             R.sup.4                                                                            physical data                             ______________________________________                                        1.40     SH      CH.sub.3                                                                              CH.sub.3                                                                            H                                              1.41     H       CH.sub.3                                                                              CH.sub.3                                                                            H                                              1.42     SH      CH.sub.3                                                                              CH.sub.3                                                                            CH.sub.3                                       1.43     H       CH.sub.3                                                                              CH.sub.3                                                                            CH.sub.3                                       ______________________________________                                    

                  TABLE 2                                                         ______________________________________                                         ##STR15##                                                                    comp.                                                                         No.   R.sup.1 R.sup.2 Y        q    physical data                             ______________________________________                                        2.1   SH      CH.sub.3                                                                              CH.sub.2 4                                              2.2   H       CH.sub.3                                                                              CH.sub.2 4    mp. 151-152° C.                    2.3   H       H       CH.sub.2 4                                              2.4   SH      CH.sub.3                                                                              CH.sub.2 3                                              2.5   H       CH.sub.3                                                                              CH.sub.2 3                                              2.6   H       H       CH.sub.2 3                                              2.7   SH      CH.sub.3                                                                              CH.sub.2 3    trans                                     2.8   SH      CH.sub.3                                                                              CH.sub.2 3    cis                                       2.9   H       CH.sub.3                                                                              CH.sub.2 3    trans                                     2.10  H       CH.sub.3                                                                              CH.sub.2 3    cis                                       2.11  H       H       CH.sub.2 3    trans                                     2.12  H       H       CH.sub.2 3    cis                                       2.13  SH      CH.sub.3                                                                              CH.sub.2 2                                              2.14  H       CH.sub.3                                                                              CH.sub.2 2                                              2.15  H       H       CH.sub.2 2                                              2.16  SH      CH.sub.3                                                                              CH.sub.2 1                                              2.17  H       CH.sub.3                                                                              CH.sub.2 1                                              2.18  H       H       CH.sub.2 1                                              2.19  SH      CH.sub.3                                                                              O        4    (4aα, 10β, 10aα)         2.20  H       CH.sub.3                                                                              O        4    .HNO.sub.3.1/2H.sub.2 O/mp.                                                   184.6° C.                                                              (4aα, 10β, 10aα)         2.21  H       H       O        4                                              2.22  SH      CH.sub.3                                                                              O        3                                              2.23  H       CH.sub.3                                                                              O        3                                              2.24  H       H       O        3                                              2.25  SH      CH.sub.3                                                                              S        4                                              2.26  H       CH.sub.3                                                                              S        4                                              2.27  H       H       S        4                                              2.28  SH      CH.sub.3                                                                              SO       4                                              2.29  H       CH.sub.3                                                                              SO       4                                              2.24  SH      CH.sub.3                                                                              SO.sub.2 4                                              2.25  H       CH.sub.3                                                                              SO.sub.2 4                                               2.26  SH      CH.sub.3                                                                              ##STR16##                                                                              4                                              2.27  H       CH.sub.3                                                                              ##STR17##                                                                              4                                             2.28  SH      CH.sub.3                                                                              NCH.sub.3                                                                              4                                              2.29  H       CH.sub.3                                                                              NCH.sub.3                                                                              4                                              ______________________________________                                    

                  TABLE 3                                                         ______________________________________                                         ##STR18##                                                                    comp.                                                                         No.       R.sup.1  R.sup.2  q   physical data                                 ______________________________________                                        3.1       SH       CH.sub.3 4                                                 3.2       H        CH.sub.3 4   mp. 139.9° C.                          3.3       H        H        4                                                 3.4       SH       CH.sub.3 3                                                 3.5       H        CH.sub.3 3                                                 3.6       H        H        3                                                 3.7       SH       CH.sub.3 1                                                 3.8       H        CH.sub.3 1                                                 ______________________________________                                    

                  TABLE 4                                                         ______________________________________                                         ##STR19##                                                                    comp.                                                                         No.   R.sup.1                                                                              R.sup.2      q    physical data                                  ______________________________________                                        4.1   SH     CH.sub.3     3    A; mp. 154.2° C.                        4.2   H      CH.sub.3     3    A; .HNO.sub.3 /mp. 148.1° C.            4.3   H      H            3    A; mp. 216.6° C.                        4.4   SH     C.sub.2 H.sub.5                                                                            3                                                   4.5   H      C.sub.2 H.sub.5                                                                            3                                                   4.6   SH     i-C.sub.3 H.sub.7                                                                          3                                                   4.7   H      i-C.sub.3 H.sub.7                                                                          3                                                   4.8   SH     CH.sub.3     1    solid residue                                  4.9   H      CH.sub.3     1    HNO.sub.3 /mp. 169.0° C.                4.10  H      C.sub.2 H.sub.5                                                                            3                                                   4.11  H      CH.sub.2CHCH.sub.2                                                                         1                                                   4.12  H      CH.sub.2CHCH.sub.2                                                                         1                                                   ______________________________________                                    

                  TABLE 5                                                         ______________________________________                                         ##STR20##                                                                    Comp.                                                                         No.    R.sup.1 R.sup.2 R.sup.3                                                                            q     Physical data                               ______________________________________                                        5.1    SH      CH.sub.3                                                                              H    1     solid residue                               5.2    H       CH.sub.3                                                                              H    1     HCl/mp. 153.6° C.                    5.3    H       H       H    1     mp. 230.0° C.                        5.4    H       C.sub.2 H.sub.5                                                                       H    1                                                 5.5    SH      CH.sub.3                                                                              H    2                                                 5.6    H       CH.sub.3                                                                              H    2                                                 5.7    H       H       H    2                                                 5.8    SH      CH.sub.3                                                                              CH.sub.3                                                                           1                                                 5.9    H       CH.sub.3                                                                              CH.sub.3                                                                           1                                                 5.10   H       H       CH.sub.3                                                                           1                                                 5.11   SH      CH.sub.3                                                                              C.sub.2 H.sub.5                                                                    1                                                 5.12   H       CH.sub.3                                                                              C.sub.2 H.sub.5                                                                    1                                                 5.13   H       H       C.sub.2 H.sub.5                                                                    1                                                 ______________________________________                                    

                  TABLE 6                                                         ______________________________________                                         ##STR21##                                                                    comp.                            physical                                     No.        R.sup.1  R.sup.2  p   data                                         ______________________________________                                        6.1        SH       CH.sub.3 1                                                6.2        H        CH.sub.3 1                                                6.3        H        H        1                                                6.4        SH       CH.sub.3 2                                                6.5        H        CH.sub.3 2                                                6.6        H        H        2                                                ______________________________________                                    

C. Composition examples

EXAMPLE 8: Composition examples for solid compounds of formula (I)(percentages are by weight)

    ______________________________________                                        (a) Wettable powders       (a)    (b)  (c)                                    ______________________________________                                        compound of formula (I)                                                                              20%    50%    0.5%                                     sodium lignosulfonate  5%     5%     5%                                       sodium laurylsulfate   3%     --     --                                       sodium diisobutylnaphthalenesulfonate                                                                --     6%     6%                                       octylphenol polyethylene glycol ether                                                                --     2%     2%                                       (7-8 moles of ethylene oxide)                                                 highly dispersed silicic acid                                                                        5%     27%    27%                                      kaolin                 67%    10%    --                                       sodium chloride        --     --     59.5%                                    ______________________________________                                    

The active ingredient was thoroughly mixed with the adjuvants and themixture was thoroughly ground in a suitable mill, affording wettablepowders which could be diluted with water to give suspensions of thedesired concentration.

    ______________________________________                                        (b)  Emulsifiable concentrate                                                                            (a)     (b)                                        ______________________________________                                        compound of formula (I)                                                                              10%     1%                                             octylphenol polyethylene glycol ether                                                                3%      3%                                             (4-5 moles of ethylene oxide)                                                 calcium dodecylbenzenesulfonate                                                                      3%      3%                                             castor oil polyglycol ether                                                   (36 moles of ethylene oxide)                                                                         4%      4%                                             cyclohexanone          30%     10%                                            dimethylbenzene mixture                                                                              50%     79%                                            ______________________________________                                    

Emulsions of any required concentration could be obtained from thisconcentrate by dilution with water.

    ______________________________________                                        (c)   Dusts              (a)     (b)                                          ______________________________________                                        compound of formula (I)                                                                            0.1%    1%                                               talcum               99.9%   --                                               kaolin               --      99%                                              ______________________________________                                    

Usable dusts were obtained by mixing the active ingredient with thecarriers, and grinding the mixture in a suitable mill.

    ______________________________________                                        (d)   Extruder granulate                                                                              (a)     (b)                                           ______________________________________                                        compound of formula (I)                                                                           10%     1%                                                sodium lignosulfate 2%      2%                                                carboxymethylcellulose                                                                            1%      1%                                                kaolin              87%     96%                                               ______________________________________                                    

The active ingredient was mixed and ground with the adjuvants, and themixture was subsequently moistened with water. The mixture was extrudedand dried in a stream of air.

    ______________________________________                                        (e)    Coated granulate                                                       ______________________________________                                        compound of formula (I) 3%                                                    polyethylene glycol (mol. wt. 200)                                                                    2%                                                    kaolin                  95%                                                   ______________________________________                                    

The finely grounded active ingredient was uniformly applied, in a mixer,to the kaolin moistened with polyethylene glycol. Non-dusty coatedgranulates were obtained in this manner.

    ______________________________________                                        (f)  Suspension concentrate (a)     (b)                                       ______________________________________                                        compound of formula (I) 40%     5%                                            ethylene glycol         10%     10%                                           nonylphenol polyethylene glycol ether                                                                 6%      1%                                            (15 moles of ethylene oxide)                                                  sodium lignosulfate     10%     5%                                            carboxymethylcellulose  1%      1%                                            37% aqueous formaldehyde solution                                                                     0.2%    0.2%                                          silicone oil in the form of a 75%                                                                     0.8%    0.8%                                          aqueous emulsion                                                              water                   32%     77%                                           ______________________________________                                    

The finely ground active ingredient was intimately mixed with theadjuvants, giving a suspension concentrate from which suspension of anydesired concentration could be obtained by dilution with water.

    ______________________________________                                        (g)   Salt solution                                                           ______________________________________                                        compound of formula (I) 5%                                                    isopropylamine          1%                                                    octylphenol polyethylene glycol ether                                                                 3%                                                    (78 moles of ethylene oxide)                                                  water                   91%                                                   ______________________________________                                    

EXAMPLE 9: Composition examples for liquid active ingredients of formula(I) (throughout, percentages are by weight)

    ______________________________________                                        (a) Emulsifiable concentrates                                                                             (a)    (b)  (c)                                   ______________________________________                                        compound of formula (I) 20%    40%    50%                                     calcium dodecylbenzenesulfonate                                                                       5%     8%     5.8%                                    castor oil polyethylene glycol ether                                                                  5%     --     --                                      (36 moles of ethylene oxide)                                                  tributylphenol polyethylene glycol ether                                                              --     12%    4.2%                                    (30 moles of ethylene oxide)                                                  cyclohexanone           --     15%    20%                                     dimethylbenzene mixture 70%    25%    20%                                     ______________________________________                                    

Emulsions of any required concentration could be produced from suchconcentrate by dilution with water.

    ______________________________________                                        (b) Solutions            (a)    (b)  (c)  (d)                                 ______________________________________                                        compound of formula (I)                                                                            80%    10%     5%  95%                                   ethylene glycol monoethyl ether                                                                    20%    --     --   --                                    polyethylene glycol (MG 400)                                                                       --     70%    --   --                                     .sub.--N--methyl-2-pyrrolidone                                                                    --     20%    --   --                                    epoxidised coconut oil                                                                             --     --      1%   5%                                   petroleum distillate (boiling range                                                                --     --     94%  --                                    160-190° C.)                                                           ______________________________________                                    

These solutions were suitable for application in the form of microdrops.

    ______________________________________                                        (c)   Granulates          (a)     (b)                                         ______________________________________                                        compound of formula (I)                                                                             5%      10%                                             kaolin                94%     --                                              highly dispersed silicic acid                                                                       1%      --                                              attapulgite           --      90%                                             ______________________________________                                    

The active ingredient was dissolved in methylene chloride, the solutionwas sprayed onto the carrier, and the solution was subsequentlyevaporated off in vacuo.

    ______________________________________                                        (d)   Dusts               (a)     (b)                                         ______________________________________                                        compound of formula (I)                                                                             2%      5%                                              highly dispersed silicic acid                                                                       1%      5%                                              talcum                97%     --                                              kaolin                --      90%                                             ______________________________________                                    

Ready-for-use dusts were obtained by intimately mixing the carriers withthe active ingredient.

D. Biological examples

EXAMPLE 10: Preemergence herbicidal activity

In the greenhouse, seeds of test plants are sown in plastic pots, filledwith a sandy soil which subsequently are covered by a 0.5 cm layer ofthe same soil. The test compounds are dissolved in aceton (100 mgcompound in 4 ml aceton), and further diluted with tap water immediatelybefore application. Each pot receives 20 ml test solution, which isevenly distributed over the soil surface by means of a plastic syringe.The dilution of the test solution is made in such a way that the amountof active ingredient, per pot, is 4 kg per hectare in the first test,and 2 kg per hectare in the second test. Test plants are mentioned inthe table 1.

During the whole test period (4 weeks) the ptos are kept on benchesunder normal greenhouse conditions. Temperature and humidity fluctuateaccording to the time of the day and to the season.

The herbicidal activity is evaluated by scoring the above-ground growthof the plant following a semi-logarithmic scale:

    ______________________________________                                        1:    no effect (growth comparable to the untreated plants).                  2:    2.5% effect                                                             3:    5% effect                                                               4:    10% effect                                                              5:    15% effect                                                              6:    25% effect                                                              7:    35% effect                                                              7-8:  50% effect                                                              8:    67.5% effect                                                            9:    100% effect (complete killing of the plants)                            ______________________________________                                         note:                                                                         a score 8.9 indicates that the herbicidal activity was about 85%, whereas     a score (8) 9 indicates that said activity was closer to 9 than to 8 and      (9) closer to 8 than to 9.                                               

    ______________________________________                                                    rates in kg/ha                                                                Compound 1.4    Compound 4.2                                                  4      2        4        2                                        ______________________________________                                        Lolium        8.9      6        9      6                                      Echinochloa   9        9        9      6                                      Setaria       (8)9     8        (8)9   8.9                                    Bromus        8        6        8      9                                      Poa           9        (8)9     9      9                                      Digitaria     9        9        9      9                                      Avena fatua   (7)8     6        (7)8   3                                      ______________________________________                                    

    ______________________________________                                                  rates in kg/ha                                                                Compound     Compound     Compound                                            4.5          5.2          5.3                                                 4     2      4      2     4     2                                   ______________________________________                                        Lolium      8.9     6      9    (8)9  3     1                                 Echinochloa 7       8      9    9     9     8.9                               Setaria     9       8      9    9     9     8                                 Bromus      6       3      9    8.9   8     1                                 Poa         9       8      9    9     9     8                                 Digitaria   9       7      9    9     8.9   7                                 Avena fatua 6       6      9    7.8   9     1                                 ______________________________________                                    

EXAMPLE 11: Herbicidal action against paddy rice associated weeds

Paddy rice was sown in plastic containers (60 cm² surface, 500 ml byvolume) together with either the seeds of the waterweeds Echinochloacrus galli or Monochoria vaginalis. The containers were watered up tothe soil surface and after three days the water level was raisedslightly above the soil surface (3-5 mm). Three days after sowing anaqueous emulsion of the active compound was applied by spraying thecontainers at a rate of application of 4 kg of a.i. per hectare(dilution 550 l/ha). The containers were kept in a greenhouse for threeweeks under conditions optimal for the waterweeds, i.e. at a temperaturebetween 20° and 25° C. and under high humidity.

The evaluation of the tests was made in accordance with the rating givenin example 10.

Results

Dosage: 4 kg a.i. per hectare

    ______________________________________                                        Comp. No.     Echinochloa                                                                              Monochoria                                           ______________________________________                                        1.4           9          9                                                    2.2           9          9                                                    4.1           9          9                                                    4.2           9          9                                                    4.3           9          9                                                    ______________________________________                                    

We claim:
 1. A chemical compound having the formula ##STR22## astereochemically isomeric form thereof, or a salt thereof, wherein R¹ ishydrogen or mercapto,R² is hydrogen, C₁ -C₇ alkyl, C₃ -C₇ alkenyl, C₃-C₇ alkynyl, C₃ -C₇ cycloalkyl, C₁ -C₇ alkyloxy-C₁ -C₇ alkyl or arylC₁-C₅ alkyl; X is a radical of formula ##STR23## wherein Y is CH₂ ; n is1, 2 or 3; A is a C₁ -C₅ alkanediyl or a C₅ -C₇ cycloalkanediyl radical;R³, R⁴, R⁵ and R⁶ are each independently hydrogen, C₁ -C₅ alkyl, mono-and di(aryl)C₁ -C₅ alkyl, C₁ -C₅ alkyloxy, halo, C₃ -C₇ alkenyl, C₁ -C₅alkyl substituted with one to three halo atoms, C₁ -C₅ alkyloxysubstituted with one to three halo atoms, or aryl; whereby the radicalsR³, R⁴ and the bivalent radical A as defined above may be substituted onany carbon atom making up the Y-containing part of the tricyclic ringsystem, including any of the CH₂ moieties of the --(CH₂)_(n) -- and Yfragments; provided that the bivalent radical A is not connected to thesame carbon atom thus forming a spirocyclic ring system; R⁷ and R⁸ areeach independently hydrogen, C₁ -C₅ alkyl, C₁ -C₅ alkyloxy, halo, C₁ -C₅alkyl substituted with one to three halo atoms, C₁ -C₅ alkyloxysubstituted with one to three halo atoms, cyano, nitro, amino, mono- anddi-C₁ -C₅ alkylamino or C₁ -C₆ alkylcarbonylamino; and aryl is phenyloptionally substituted with one to three substituents each independentlyselected from C₁ -C₅ alkyl, C₁ -C₅ alkyloxy and halo.
 2. A compoundaccording to claim 1 wherein R² is hydrogen or C₁ -C₇ alkyl; A is a C₁-C₅ alkanediyl group being substituted with R⁵ and R⁶ ; and R⁷ and R⁸are each independently hydrogen, halo, C₁ -C₅ alkyl, C₁ -C₅ alkyloxy,cyano or C₁ -C₆ alkylcarbonylamino.
 3. A compound according to claim 2wherein A is C₃₋₅ alkanediyl; R³, R⁴, R⁵ and R⁶ are each independentlyhydrogen or C₁₋₅ alkyl.
 4. A compound according to claim 3 wherein R² ishydrogen, methyl or ethyl; n is 1 or 2; A is a C₃ -C₄ alkanediyl group;R³, R⁴, R⁵ and R⁶ are each independently hydrogen or methyl; and R⁷ andR⁸ are each independently hydrogen, methyl, methoxy or halo.
 5. Acompound according to claim 1 wherein the compound is selected frommethyl1-(1,2,3,4,4a,9a-hexahydro-9H-fluoren-9yl)-1H-imidazole-5-carboxylateand methyl1-(5,6,7,8-tetrahydro-5,8-methano-9H-benzocyclohept-9-yl)-1H-imidazole-5-carboxylate.6. A herbicidal composition comprising an inert carrier and, if desired,other adjuvants, and as active ingredient a herbicidally effectiveamount of a chemical compound having the formula (I) as claimed inclaim
 1. 7. A herbicial composition according to claim 6 wherein R² ishydrogen or C₁ -C₇ alkyl; A is a C₁ -C₅ alkanediyl group beingsubstituted with R⁵ and R⁶ ; and R⁷ and R⁸ are each independentlyhydrogen, halo, C₁ -C₅ alkyl, C₁ -C₅ alkyloxy, cyano or C₁ -C₆alkylcarbonylamino.
 8. A herbicidal composition according to claim 7wherein A is C₃₋₅ alkanediyl; R³, R⁴, R⁵ and R⁶ are each independentlyhydrogen or C₁₋₅ alkyl.
 9. A herbicidal composition according to claim 8wherein R² is hydrogen, methyl or ethyl; n is 1 or 2; A is a C₃ -C₄alkanediyl group; R³, R⁴, R⁵ and R⁶ are each independently hydrogen ormethyl; and R⁷ and R⁸ are each independently hydrogen, methyl, methoxyor halo.
 10. A herbicidal composition according to claim 6 wherein inthe compound is selected from methyl1-(1,2,3,4,4a,9a-hexahydro-9H-fluoren-9-yl)-1H-imidazole-5-carboxylateand methyl1-(5,6,7,8-tetrahydro-5,8-methano-9H-benzocyclohept-9-yl)-1H-imidazole-5-carboxylate.11. A method for controlling weeds, which method comprises applying tosaid weeds or to the locus thereof of a herbicidally effective amount ofa chemical compound having the formula (I) as claimed in claim
 1. 12. Amethod according to claim 11 for selectively controlling weeds in cropsof useful plants.
 13. A method according to claim 12 wherein the crop isone or more of rice, maize and other cereals.
 14. A method according toclaim 12 wherein the crop is rice and the rice is transplanted rice. 15.A method according to claim 13 wherein 0.01 to 5.0 kg of activeingredient per hectare are applied to areas where rice crops are grown.16. A method according to claim 15 wherein 0.05 to 1 kg of the activeingredient is applied per hectare after transplanting the riceplantlets.
 17. A method according to claim 11 wherein R² is hydrogen orC₁ -C₇ alkyl; Y is O, S or CH₂ ; A is a C₁ -C₅ alkanediyl group beingsubstituted with R⁵ and R⁶ ; and R⁷ and R⁸ are each independentlyhydrogen, halo, C₁ -C₅ alkyl, C₁ -C₅ alkyloxy, cyano or C₁ -C₆alkylcarbonylamino.
 18. A method according to claim 17 wherein Y is O orCH₂ ; A is C₃₋₅ alkanediyl; R³, R⁴, R⁵ and R⁶ are each independentlyhydrogen or C₁₋₅ alkyl.
 19. A method according to claim 18 wherein R² ishydrogen, methyl or ethyl; n is 1 or 2; A is a C₃ -C₄ alkanediyl group;R³, R⁴, R⁵ and R⁶ are each independently hydrogen or methyl; and R⁷ andR⁸ are each independently hydrogen, methyl, methoxy or halo.
 20. Amethod according to claim 11 wherein in the compound is selected frommethyl1-(1,2,3,4,4a,9a-hexahydro-9H-fluoren-9-yl)-1H-imidazole-5-carboxylateand methyl1-(5,6,7,8-tetrahydro-5,8-methano-9H-benzocyclohept-9-yl)-1H-imidazole-5-carboxylate.